1. Technical Field
The present disclosure relates to measuring devices, and particularly, to an auxiliary device for helping to measure coaxiality of lenses having a curved surface and a flat surface opposite to the curved surface.
2. Description of Related Art
To obtain high imaging quality, it is required that the two optical surfaces are strictly coaxial. However, it is difficult to machine a mold in which a lens is made having two precise coaxial optical surfaces, limited to manufacturing precision. Before obtaining the coaxiality of the lens, an eccentricity of the lens should be measured. Currently, lenses with a curved optical surface and a flat optical surface have been proposed. With the lack of one curved optical surface, the eccentricity of the lens cannot be measured directly.
Therefore, it is desirable to provide an auxiliary device for helping to measure coaxiality of lenses which can overcome the above-mentioned shortcomings.